On March 12, 1948, at 9:14 p.m. Pacific Standard Time, Northwest Airlines Flight 4422 crashed into Mount Sanford, a peak in the remote Wrangell Mountains in eastern Alaska. All 24 passengers—merchant mariners returning to the U.S. from Shanghai, China—along with six Northwest crew members, probably died on impact. The debris, too difficult to reach, was quickly covered by snow and eventually entombed by ice.

There it remained until 1999, despite many failed efforts to find it. In that year Kevin McGregor and Marc Millican, two former U.S. Air Force pilots who like to solve forgotten aviation mysteries, having determined that the glacier containing the plane was retreating, gained permission from the National Park Service to recover parts of the wreckage if they could find it. After an arduous climb, they discovered scattered debris, along with a desiccated left arm and attached hand in the ice. As McGregor explains, “That changed the entire project. We became compelled to find out to whom the arm and hand belonged.”